My XX deal with Sister Nero

OK, now the question is, I have traveled through time, I have a beautiful sister who is above everyone else and has a brother-control attribute, and this sister looks very familiar, how can I avoid having my legs broken and sent to the Germans next door? In addition, I also met a very gentle sister Marta, a purple old woman and her big black dog, how can I survive in such an environment, waiting online is really urgent